1. Field of Invention
The invention relates to a parts procurement system and method that allows a parts order required to manufacture objects (e.g., vehicles) manufactured on a production line to be made at the appropriate time.
2. Description of Related Art
It has conventionally been necessary to properly procure parts during the course of assembly for products such as automobiles and other vehicles that are composed of many parts. Accordingly, various proposals are being made so as to allow ordering of parts at proper times in accordance with the production plan.
For example, Japanese Patent Application Laid-Open No. 8-190586 proposes a parts procurement system in which judgment as to when to make a parts order is made based on when the parts are used, lead time necessary for the delivery of parts from the time an order is placed, the number of parts used, and the like, and selecting an appropriate ordering method thereby.
The parts ordering methods include a replenishment method in which orders are placed to replenish the parts that have been used, a production stage ordering method in which orders are placed at an actual production stage, and a production planning stage ordering method in which orders are placed when a production plan is fixed.
By adopting these ordering methods as appropriate, parts are ordered at appropriate times, thereby preventing a shortage of parts and enabling the number of stocked parts to be decreased.
However, the above-mentioned technique is built on an assumption that the lead time for parts delivery is relatively short, and therefore does not deal with cases with long delivery lead times. That is, there are no methods provided which cover those parts that cannot be delivered in time if the order is placed after the production plan is fixed. In the case of such parts with long delivery lead times, usually a long-term plan is made before the production plan is fixed so as to make orders based on that long-term plan. However, there are many cases where the actual production is not carried out as planned by the long-term plan, resulting in a shortage of parts or unnecessary stock of parts.